Bug 8477 - Mono fails to load valid program * Assertion at cominterop.c:331, condition `MONO_CLASS_IS_INTERFACE (ic)' not met
Summary: Mono fails to load valid program * Assertion at cominterop.c:331, condition `...
Alias: None
Product: Runtime
Classification: Mono
Component: Remoting ()
Version: 5.4 (2017-06)
Hardware: PC Mac OS
: Normal normal
Target Milestone: Future Cycle (TBD)
Assignee: Bugzilla
Depends on:
Reported: 2012-11-17 16:25 UTC by Marek Safar
Modified: 2017-10-19 19:33 UTC (History)
5 users (show)

Tags: bugpool-archive
Is this bug a regression?: ---
Last known good build:

test-859 (3.50 KB, application/x-msdownload)
2012-11-17 16:25 UTC, Marek Safar
test-859-lib (2.00 KB, application/x-msdownload)
2012-11-17 16:26 UTC, Marek Safar

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Description Marek Safar 2012-11-17 16:25:14 UTC
Created attachment 2959 [details]

mono test-859.exe

* Assertion at cominterop.c:331, condition `MONO_CLASS_IS_INTERFACE (ic)' not met


  at <unknown> <0xffffffff>
  at X.Main () <0x00023>
  at (wrapper runtime-invoke) <Module>.runtime_invoke_int (object,intptr,intptr,intptr) <0xffffffff>
Comment 1 Marek Safar 2012-11-17 16:26:05 UTC
Created attachment 2960 [details]
Comment 2 Rodrigo Kumpera 2017-07-14 23:30:33 UTC
I can repro this bug with master.
Comment 3 Ludovic Henry 2017-09-11 20:49:27 UTC
It reproduces with Mono (2017-06/6425f06)
Comment 4 Marek Safar 2017-09-13 15:11:18 UTC
The sample works (don't crash) on .NET
Comment 5 Vladimir Kargov 2017-09-20 14:10:57 UTC
test-589.exe contains code that attempts to execute an incomplete internal call. However, the branch executing that code is not taken: 
.class private auto ansi beforefieldinit X 
       extends [mscorlib]System.Object 
  .method private hidebysig instance void  
          Test_PropertyOptionalParameters(class ['test-859-lib']C c) cil managed 
    // Code size       46 (0x2e) 
    .maxstack  8 
    IL_0000:  nop 
    IL_0001:  ldarg.1 
// Not taken 
    IL_0002:  brtrue     IL_000c 
// Jump to safety (taken) 
    IL_0007:  br         IL_002d 
    IL_000c:  ldarg.1 
    IL_000d:  ldsfld     class [mscorlib]System.Reflection.Missing [mscorlib]System.Reflection.Missing::Value 
    IL_0012:  callvirt   instance object ['test-859-lib']C::get_Value(object) 
// (...) 
    IL_002d:  ret 
  } // end of method X::Test_PropertyOptionalParameters 
  .method private hidebysig static int32  
          Main() cil managed 
    // Code size       23 (0x17) 
    .maxstack  2 
    .locals init (class X V_0, 
             int32 V_1) 
    IL_0000:  nop 
    IL_0001:  newobj     instance void X::.ctor() 
    IL_0006:  stloc.0 
    IL_0007:  ldloc.0 
    IL_0008:  ldnull 
    IL_0009:  callvirt   instance void X::Test_PropertyOptionalParameters(class ['test-859-lib']C) 
// (...) 
  } // end of method X::Main 
AFAIU this happens because Mono relies on the validity of the entire function (Test-PropertyOptionalParameters) while .NET is more "tolerant" and doesn't crash on bad code that doesn't get executed.

I believe that generating an unreachable code trap instead of failing on an assertion during compilation would be the right way to fix it.
Comment 6 Ludovic Henry 2017-09-26 19:08:17 UTC